Semiconductor bonding structure and process

ABSTRACT

A system and method for bonding semiconductor devices is provided. An embodiment comprises halting the flow of a eutectic bonding material by providing additional material of one of the reactants in a grid pattern, such that, as the eutectic material flows into the additional material, the additional material will change the composition of the flowing eutectic material and solidify the material, thereby stopping the flow. Other embodiments provide for additional layouts to put the additional material into the path of the flowing eutectic material.

This application is a continuation of U.S. patent application Ser. No.13/660,374, filed Oct. 25, 2012, and entitled “Semiconductor BondingStructure and Process,” which application is hereby incorporated hereinby reference.

BACKGROUND

Generally, a first semiconductor device with a particular functionalitymay be utilized with a second semiconductor device that may have adifferent, yet complementary, functionality in order to obtain thebenefits from both the first semiconductor device and the secondsemiconductor device. Alternatively, a substrate such as a printedcircuit board or interposer may be utilized to help provide connectivityand support to the first semiconductor device. These devices may bephysically and electrically connected to each other using a physical andelectrical bonding technique.

Such bonding techniques serve a dual purpose. In a first purpose anymaterial chosen to help bond the first semiconductor device to thesecond semiconductor device provides an electrically conductive pathbetween electrical connections on the first semiconductor device and thesecond semiconductor device. As such, the material chosen conductselectricity and also forms an electrical bridge between the electricalconnections.

In the other purpose the material chosen to bond the first semiconductordevice to the second semiconductor device provides a level of physicalconnection between the first semiconductor device and the secondsemiconductor device. Without such a physical connection, the firstsemiconductor device may not be fully supported in relation to itspositions with the second semiconductor device. As such, during movementor even during normal operation and use the first semiconductor devicemay shift its position, causing the alignment of the electricalconnections on the first semiconductor device and the electricalconnections on the second semiconductor device to shift and potentiallycausing the electrical connections to become unconnected, leading to aninability of the first semiconductor device and the second semiconductordevice to exchange electrical signals with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIGS. 1A-1B illustrate a first semiconductor device and a secondsemiconductor device to be bonded in accordance with an embodiment;

FIGS. 2A-2B illustrate contact a first bonding material with a secondbonding material in accordance with an embodiment;

FIGS. 3A-3B illustrate halting the flow of a eutectic bonding materialin accordance with an embodiment;

FIGS. 4A-4E illustrate patterns that may be utilized to halt theeutectic bonding material in accordance with an embodiment;

FIGS. 5A-5B illustrate patterns that may be used with the first bondingmaterial to assist to halting the flow of the eutectic bonding materialin accordance with an embodiment; and

FIG. 6 illustrates trenches that may be utilized along with the patternsin accordance with an embodiment.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the present embodiments are discussed in detailbelow. It should be appreciated, however, that the present disclosureprovides many applicable inventive concepts that can be embodied in awide variety of specific contexts. The specific embodiments discussedare merely illustrative of specific ways to make and use the disclosedsubject matter, and do not limit the scope of the different embodiments.

Embodiments will be described with respect to a specific context, namelya eutectic bonding of two semiconductor devices. Other embodiments mayalso be applied, however, to other bonding processes.

With reference now to FIG. 1A, there is shown a first semiconductordevice 101 and a second semiconductor device 103 that will be bonded tothe first semiconductor device 101. In an embodiment the firstsemiconductor device 101 may be a semiconductor die with functionalcircuitry designed to provide a desired functionality while the secondsemiconductor device 103 may also be a semiconductor die with functionalcircuitry designed to work with or complement the functionality of thefirst semiconductor device 101. Alternatively, one of the firstsemiconductor device 101 and the second semiconductor device 103 maycomprise functional circuitry, while the other one provides additionalconnectivity and routing, such as being an interposer or other type ofpackaging. Any suitable combination of devices that may be electricallyor physically bonded together are fully intended to be included withinthe scope of the embodiments.

The first semiconductor device 101 may comprise a first substrate 105,first active devices 107, first metallization layers 109, a firstpassivation layer 111, and a first bonding material 113. The firstsubstrate 105 may comprise bulk silicon, doped or undoped, or an activelayer of a silicon-on-insulator (SOI) substrate. Generally, an SOIsubstrate comprises a layer of a semiconductor material such as silicon,germanium, silicon germanium, SOL silicon germanium on insulator (SGOI),or combinations thereof. Other substrates that may be used includemulti-layered substrates, gradient substrates, or hybrid orientationsubstrates. Additionally, interposer substrates or organic substratesmay also be included within the scope.

The first active devices 107 (only one of which is illustrated in FIG.1A for clarity) may be formed on the first substrate 105. As one ofordinary skill in the art will recognize, the first active devices 107may include a wide variety of active and passive devices such ascapacitors, resistors, inductors and the like may be used to generatethe desired structural and functional requirements of the design for thefirst semiconductor device 101. The first active devices 107 may beformed using any suitable methods either within or else on the surfaceof the first substrate 105.

The first metallization layers 109 may be formed over the firstsubstrate 105 and the first active devices 107 and are designed toconnect the various active devices 107 to form functional circuitry.While illustrated in FIG. 1A as a single layer, the first metallizationlayers 109 may be formed of alternating layers of dielectric (e.g.,low-k dielectric material) and conductive material (e.g., copper) andmay be formed through any suitable processes (such as deposition,damascene, dual damascene, etc.). In an embodiment there may be fourlayers of metallization separated from the first substrate 105 by atleast one interlayer dielectric layer (ILD), but the precise number offirst metallization layers 109 is dependent upon the design of the firstsemiconductor device 101.

The first passivation layer 111 may be formed on the first substrate 105over the first metallization layers 109. The first passivation layer 111may be made of one or more suitable dielectric materials such as siliconoxide, silicon nitride, low-k dielectrics such as carbon doped oxides,extremely low-k dielectrics such as porous carbon doped silicon dioxide,combinations of these, or the like. The first passivation layer 111 maybe formed through a process such as chemical vapor deposition (CVD),although any suitable process may be utilized, and may have a thicknessbetween about 0.5 μm and about 5 μm, such as about 9.25 KÅ.

The first bonding material 113 may be formed over and through the firstpassivation layer 111 in order to provide an electrical connectionbetween the first metallization layers 109 and the second semiconductordevice 103 (the bonding process is described further below with respectto FIGS. 2A-3B). In an embodiment the first bonding material 113 may beutilized along with a second bonding material 123 (described furtherbelow) in order to form a eutectic bond between the first bondingmaterial 113 and the second bonding material 123. This bonding may beutilized to provide the physical and electrical bonds between the firstsemiconductor device 101 and the second semiconductor device 103.

As such, the material utilized for the first bonding material 113 iscomplementary to the material utilized for the second bonding material123 to obtain a eutectic bond. As such, while the precise materialschosen for the first bonding material 113 is dependent at least in parton the material chosen for the second bonding material 123, in anembodiment in which the second bonding material 123 is chosen to bealuminum, the first bonding material 113 may be a eutectic bondingmaterial such as germanium or silicon. However, if the second bondingmaterial 123 is germanium, the first bonding material 113 may bealuminum. Alternatively, in an embodiment in which the second bondingmaterial 123 is silicon, the first bonding material 113 may be aluminumor gold. Any suitable combination of materials for the first bondingmaterial 113 and the second bonding material 123 that will form aeutectic bond may alternatively be utilized, and all such combinationsare fully intended to be included within the scope of the embodiments.The first bonding material 113 may be formed using physical vapordeposition (PVD) or chemical vapor deposition (CVD), although any othersuitable process may alternatively be utilized.

The first bonding material 113 may be one or more layers of materials,and may be sized and shaped to provide enough of the first bondingmaterial 113 to react with a portion of a second bonding material 123located on the second semiconductor device 103 (as described furtherbelow with respect to FIGS. 2A-3B). Additionally, in an embodiment thesecond bonding material 123 is patterned such that individual patternsin the second bonding material 123 are not enough form a eutecticcompound with the first bonding material 113. As such, the reactionbetween the first bonding material 113 and the second bonding material123 will be reactant limited as a eutectic product of the reactionbegins to spread. By limiting the reaction that produces the eutecticproduct, the lateral spread of the eutectic product will also belimited, thereby preventing the spread of the eutectic product anylimiting any undesired electrical shorts from forming.

As such, while the precise dimensions of the first bonding material 113may be determined in part based upon the material and amount of thesecond bonding material 123, in an embodiment in which the secondbonding material 123 is aluminum and shaped as discussed below, thefirst bonding material 113 may be formed in a block shape with a firstlength l₁ of between about 2 μm and about 80 μm, such as about 30 μm,and a first width w₁ of between about 2 μm and about 80 μm, such asabout 30 μm. Additionally, the first bonding material 113 may have afirst thickness t₁ of between about 0.1 μm and about 1 μm, such as about0.5 μm.

The second semiconductor device 103 may comprise a second substrate 115,second active devices 117, second metallization layers 119, a secondpassivation layer 121, and a second bonding material 123. In anembodiment the second substrate 115, the second active devices 117, thesecond metallization layers 119, and the second passivation layer 121may be similar to the first substrate 105, the first active devices 107,the first metallization layers 109, and the first passivation layer 111,respectively. Alternatively, the second substrate 115, the second activedevices 117, the second metallization layers 119, and the secondpassivation layer 121 may be different from the first substrate 105, thefirst active devices 107, the first metallization layers 109, and thefirst passivation layer 111. Additionally, as described above, thesecond semiconductor device 103 may comprise no second active devices117 and may be an interposer or other type of substrate used to provideconnectivity and support to the first semiconductor device 101.

The second bonding material 123 may be one or more layers formed overand through the second passivation layer 121 in order to provide anelectrical connection between the second metallization layers 119 andthe first semiconductor device 101 (the bonding process is describedfurther below with respect to FIGS. 2A-3B). In an embodiment the secondbonding material 123 is a complementary material with the first bondingmaterial 113 such that, when the two materials are mixed at anappropriate temperature and composition, a eutectic compound is formed.As such, while the precise material of the second bonding material 123is dependent at least in part on the material chosen for the firstbonding material 113, in an embodiment in which the first bondingmaterial 113 is germanium the second bonding material 123 may be, e.g.,aluminum. However, any other suitable material pairs, such as gold-gold,copper-copper, Aluminum-Aluminum, Al—Si, Au—Si, Au—Ge, or the like, mayalternatively be utilized.

The second bonding material 123 may be formed using a deposition processsuch as chemical vapor deposition (CVD), plasma assisted chemical vapordeposition (PECVD), physical vapor deposition (PVD), combinations ofthese, or the like, in order to form a blanket layer (not individuallyillustrated in FIG. 1A) of the second bonding material 123. Once theblanket layer of the second bonding material 123 has been formed, theblanket layer of the second bonding material 123 is patterned in such afashion as to provide an initiating amount of the second bondingmaterial 123 and a halting amount of the second bonding material 123. Inan embodiment the initiating amount is used to initiate eutecticreaction with the first bonding material 113 and, at intervalssurrounding the initial amount of the second bonding material 123, thehalting amount is utilized to help drive the compound out of theeutectic phase.

For example, FIG. 1B illustrates one embodiment of the second bondingmaterial along line B-B′ in FIG. 1A in which the second bonding material123 is patterned in a grid pattern, with an inner initiating amount ofthe second bonding material 123 (represented in the dashed box labeled130) and an outer halting amount of the second bonding material 123(represented in the dashed box labeled 132). In this embodiment the gridpattern may be a square grid of seven individual blocks 131 of thesecond bonding material 123 per side of the grid.

Additionally, the individual blocks 131 are sized and shaped so that theinitiating amount 130 of the second bonding material 123 provides enoughof the second bonding material 123 to initiate and maintain the eutecticreaction with the first bonding material to form the eutectic product.As such, while the dimensions of the individual blocks 131 will bedependent at least in part on the size and shape of the first bondingmaterial 113, in an embodiment in which the second bonding material 123is aluminum the individual blocks 131 may have a second length l₂ ofbetween about 0.5 μm and about 5 μm, such as about 2 μm, and a secondwidth w₂ of between about 0.5 μm and about 5 μm, such as about 2 μm.

Additionally, the individual blocks 131 may have a second thickness t₂(see FIG. 1A) of between about 0.1 μm and about 2 μm, such as about 1μm, and may be spaced apart from one another a first distance d₁ ofbetween about 0.5 μm and about 5 μm, such as about 2 μm. The secondthickness t₂ may also be utilized, if desired, to precisely tune thespecific amount of the second bonding material 123 that is desired. Ifadditional second bonding material 123 is desired, for example, tomodify the composition of the eutectic compound that will form, then thesecond thickness t₂ may be increased to put additional amounts of thesecond bonding material 123 where desired. Additionally, if less secondbonding material 123 is desired, the second thickness t₂ may be reduced.

FIGS. 2A-2B illustrate a step in a bonding process whereby the firstsemiconductor device 101 and the second semiconductor device 103 areplaced in contact with each other by placing the first bonding material113 in contact with the initiating amount 130 of the second bondingmaterial 123, with FIG. 2B illustrating a plan view along line B-B′ inFIG. 2A. In an embodiment where eutectic bonding is desired, the firstbonding material 113 (e.g., germanium) and the initiating amount 130 ofthe second bonding material (e.g., aluminum) may result in a compositionsufficient to initiate a eutectic reaction between the first bondingmaterial 113 and the second bonding material 123. For example, thecombined materials of the first bonding material 113 and the initiatingamount 130 of the second bonding material 123 may have a germaniumcomposition of between about 25% and about 35%, such as about 28%, andmay have an aluminum composition of between about 65% and about 75%,such as about 72%.

To initiate the eutectic reaction between the first bonding material 113and the second bonding material 123, a temperature of the first bondingmaterial 113 and the second bonding material 123 is raised to a eutecticpoint of the materials. As such, while the precise temperature isdependent at least in part upon the materials chosen for the firstbonding material 113 and the second bonding material 123, in anembodiment in which the first bonding material 113 is germanium and thesecond bonding material 123 is aluminum as described above, thetemperature of the first bonding material 113 and the second bondingmaterial 123 may be increased to greater than the eutectic point ofabout 419° C.

When the first bonding material 113 and the second bonding material 123are in contact with each other at the right composition and theirtemperature is raised past the eutectic temperature point, the firstbonding material 113 and the second bonding material 123 will react andform a eutectic composition bonding material 201 in a liquid phase. Thiseutectic composition bonding material 201 begins to flow and providesfor the electrical connection between the first semiconductor device 101and the second semiconductor device 103.

Additionally, pressure may be added to the first bonding material 113and the second bonding material 123 by applying one or more forces tothe first semiconductor device 101 and the second semiconductor device103. The precise pressure utilized may be dependent at least in partupon the status of the first semiconductor device 101 and the secondsemiconductor device 103, such as their size, bonding area, warpage, orthe like. This pressure also helps to drive the eutectic reaction andhelps to position the first semiconductor device 101 and the secondsemiconductor device 103 for the final bonding. However, as pressure isapplied to the first semiconductor device 101 and the secondsemiconductor device 103, pressure is also applied to the eutecticcomposition bonding material 201 in its liquid phase, causing theeutectic composition bonding material 201 to flow in potentiallyuncontrollable and undesirable fashion.

FIGS. 3A-3B illustrate an embodiment that may be used to control thisflow of the eutectic composition bonding material 201. As can be seen,the eutectic composition bonding material 201, while providing for theelectrical connection between the first semiconductor device 101 and thesecond semiconductor device 103, has also begun to flow away from itsoriginal location. If left by itself, the flow of the eutecticcomposition bonding material 201 (driven by the pressure from thebonding process) may extend uncontrollably to another conductive portionof either the first semiconductor device 101 or the second semiconductordevice 103, thereby causing a undesired short-circuit.

To counter-act the undesired flow of the eutectic composition bondingmaterial 201, the halting amount 132 of the second bonding material 123is provided. As the eutectic composition bonding material 201 flows awayfrom its initial position within the center of the grid, the eutecticcomposition bonding material 201 will come into contact with theindividual blocks 131 that make up the halting amount 132 of the secondbonding material 123 that surrounds the initial location eutecticcomposition bonding material 201. This contact will help to contain theflow of the eutectic composition bonding material 201.

In particular, when the eutectic composition bonding material 201 comesinto contact with the individual blocks 131 of the halting amount 132 ofthe second bonding material 123 (e.g., aluminum), the additional secondbonding material 123 present in the halting amount 132 of the secondbonding material 123 will alter the composition of those portions of theeutectic composition bonding material 201 in immediate contact with thehalting amount 132 of the second bonding material 123. This altering ofthe composition of the eutectic composition bonding material 201 willdrive those portions of the eutectic composition bonding material 201out of the composition range that forms the eutectic compound at theprocess temperature. This will cause those portions of the eutecticcomposition bonding material 201 with the additional second bondingmaterial 123 to shift to a solid, thereby preventing the flow of theeutectic composition bonding material 201 from continuing.

Additionally, in an embodiment in which there are multiple rows of theindividual blocks 131, the further away from the initial location thatthe eutectic composition bonding material 201 flows, the greater thenumber of individual blocks 131 the eutectic composition bondingmaterial 201 will come into contact with. As such, if the eutecticcomposition bonding material 201 remains in the eutectic phase aftercontacting a first row of the individual blocks 131, the eutecticcomposition bonding material 201 will continue to flow and will contactanother row that will add even more of the second bonding material 123to the eutectic composition bonding material 201 and driving theeutectic composition bonding material 201 further away from the eutecticpoint at the temperature of the bonding process. As such, the second row(or other additional rows depending upon the number of rows utilized)will serve as a back stop to the first row.

Once the eutectic composition bonding material 201 has been used to makethe electrical connection between the first semiconductor device 101 andthe second semiconductor device 103, the bonding process may becontinued by lowering the temperature of the eutectic compositionbonding material 201 below its eutectic point. By lowering thetemperature, the eutectic composition bonding material 201 will phasechange back into a solid, thereby physically bonding the firstsemiconductor device 101 and the second semiconductor device 103. Forexample, while the precise temperature will be dependent at least inpart on the materials and compositions chosen, in an embodiment in whichthe first bonding material 113 is germanium and the second bondingmaterial 123 is aluminum in the compositions described above, thetemperature of the eutectic composition bonding material 201 may belowered below the eutectic point of about 419° C.

However, as one of ordinary skill in the art will recognize, the preciseprocess conditions, such as the process temperature utilized during thebonding process and the reduction in process temperature utilized tochange the eutectic composition back in to a solid, are at least in partdependent upon the desired compositions of the first bonding material113 and the second bonding material 123. For example, in an embodimentin which the combination of the first bonding material 113 and theinitiation portion of the second bonding material 123 has a germaniumconcentration of about 10 atom % and an aluminum concentration of about90 atom %, the process temperature may need to be increased to greaterthan around 620° C. to reach the eutectic point and may need to belowered below around 620° C. in order to make the eutectic compositionsolidify. All such variations on composition and their respectiveeutectic points and temperatures may alternatively be utilized, and allare fully intended to be included within the scope of the embodiments.

By using the halting amount 132 of the second bonding material 123 tohelp control the flow of the eutectic composition bonding material 201,the overall space required for the connection in order to make sure thatthere is no undesired connections may be reduced. This helps to reducethe pattern density, size and layout utilized for connecting the firstsemiconductor device 101 to the second semiconductor device 103, whilestill maintaining a lower contact resistance than by arbitrarilyreducing the size of the layout. Additionally, by patterning the secondbonding material 123, the pattern may also be used as a process aligneror a bonding shift monitor, thereby alleviating additional steps to formthese structures independently from the second bonding material 123.

FIGS. 4A-4E illustrate that, while the grid pattern illustrated abovewith respect to FIG. 1B is one embodiment that may be used, such adescription is not intended to limit the embodiments. Rather, a widevariety of patterns may be used to pattern the second bonding material123 in order to provide both an initiating amount 130 of the secondbonding material as well as the halting amount 132 of the second bondingmaterial. FIG. 4A illustrates that the individual blocks 131 may bearranged so as to add more second bonding material 123 at corners of thegrid pattern.

FIG. 4B illustrates that, instead of having a grid comprising similarlysized and shaped blocks 131, a series of blocks 131 and lines 133 may beutilized within the grid. By using lines 133 along with the individualblocks 131, additional halting material 131 of the second bondingmaterial 123 may be added where desired. For example, in FIG. 4Badditional material is added in lines that overlap each other along theflow path of the eutectic composition bonding material 201.

FIG. 4C illustrates that the lines 133 may be arranged in variousencircling shapes 135, such as an octagonal shape illustrated in FIG.4C. By using an encircling shape 135, the halting amount 131 of theeutectic composition bonding material 201 may, in addition to providinga halt to the eutectic reaction, may also provide a physical barrier tothe flow of the eutectic composition bonding material 201 until theeutectic reaction is halted and the eutectic composition bondingmaterial 201 resolidifies.

FIG. 4D illustrates a grid pattern laid out in a non-uniform manner. Forexample, the rows of the grid may be offset from each other. Such apattern helps to disrupt the flow of the eutectic composition bondingmaterial 201 and helps the eutectic composition bonding material 201come into contact with the halting amount 131 of the second bondingmaterial 123.

FIG. 4E illustrates yet another embodiment in which a series ofencircling shapes 135 (in this embodiment in the shape of encirclingrectangles) are utilized to help prevent the flow of the eutecticcomposition bonding material 201. By using a series of encirclingshapes, one may act as a backstop to the other in case one fails.

FIGS. 5A-5B illustrates another embodiment in which the second bondingmaterial 123 is patterned (as described above with respect to FIGS.1A-4E) and the first bonding material 113 is patterned as well. In theembodiment illustrated, the staggered grid pattern described above withrespect to FIG. 4D is utilized as the pattern for the second bondingmaterial 123. Additionally, the first bonding material is patterned, forexample, into a square pattern encircling an “I” shape. Such patterningof the first bonding material 113 allows for a flow of the eutecticcomposition bonding material 201 both towards the center of the firstbonding material 113 as well as away from the center of the firstbonding material 113.

FIG. 5B illustrates another patterning of the first bonding material 113that may be utilized. In this embodiment the first bonding material 113is patterned into a series of square shapes set out in a two by twogrid. Such a patterning allows each of the square shapes of the firstbonding material 113 to flow (once it has reacted with the secondbonding material 123) independently from each other until the flows comeinto contact.

FIG. 6 illustrates yet another embodiment that may be used inconjunction with the initiating amount 130 and the halting amount 132 ofthe second bonding material 123 to help prevent undesirable flow. Inthis embodiment trenches 601 may be formed in either the firstsemiconductor device 101 (as illustrated in FIG. 6) or in both the firstsemiconductor device 101 and the second semiconductor device 103. Thesetrenches 601 serve as a backstop to the halting amount 132 of the secondbonding material 123 and help to contain the eutectic compositionbonding material 201 in case the eutectic composition bonding material201 gets past the halting amount of the second bonding material 123.

In an embodiment the trenches may be formed utilizing, e.g., aphotolithographic masking and etching process whereby a photosensitivematerial (not individually illustrated) is applied to the firstsemiconductor device 101, exposed to a patterned energy source such aslight, and developed to form a mask. Once developed, the mask isutilized to pattern the underlying first semiconductor device 101 toform the trenches 601 using, e.g., a dry etch process, although anysuitable etching process may alternatively be utilized. The trenches 601may be formed to have a third width w₃ of between about 0.5 μm and about5 μm, such as about 2 μm, and may be formed to a depth of a seconddistance d₂ of between about 0.5 μm and about 40 μm, such as about 20μm, although any suitable dimension may alternatively be utilized.

In accordance with an embodiment, a method for bonding semiconductordevices comprising patterning a first bonding material into aninitiating portion and a halting portion and contacting the initiatingportion with a second bonding material to form a eutectic composition isprovided. The eutectic composition is flowed to the halting portion,wherein the halting portion changes the composition of the eutecticcomposition.

In accordance with another embodiment, a method of bonding semiconductordevices comprising placing a first bonding material on a first substrateinto contact with an initiating portion of a second bonding material ona second substrate to form a eutectic compound is provided. A pressureis applied to the first substrate and the second substrate, the pressureassisting a flow of the eutectic compound, the flow of the eutecticcompound causing the eutectic compound to come into contact with ahalting portion of the second bonding material on the second substrate,the halting portion altering the composition of the eutectic compoundand halting the flow of the eutectic compound.

In accordance with yet another embodiment, a semiconductor devicecomprising a passivation layer on a substrate and a first eutecticbonding material at least partially over the passivation layer isprovided. The first eutectic bonding material further comprises aninitiating portion and a halting portion surrounding the initiatingportion.

Although the present embodiments and their advantages have beendescribed in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the disclosure as defined by the appendedclaims. For example, many of the methods of formation discussed abovecan be changed or modified as desired while remaining within the scopeof the embodiments. As another example, it will be readily understood bythose skilled in the art that the various materials utilized be variedwhile still remaining within the scope of the present disclosure.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present disclosure.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

What is claimed is:
 1. A semiconductor device comprising: a passivationlayer on a substrate; a first eutectic bonding material at leastpartially over the passivation layer, the first eutectic bondingmaterial further comprising: an initiating portion with a firstcomposition; and a halting portion surrounding the initiating portion,the halting portion having a second composition different from the firstcomposition; and a block laterally separated from the first eutecticbonding material, wherein the block comprises a first material, whereinthe halting portion comprises the first material.
 2. The semiconductordevice of claim 1, wherein the first composition comprises aluminum andgermanium.
 3. The semiconductor device of claim 1, further comprising atrench formed within the passivation layer.
 4. The semiconductor deviceof claim 1, further comprising a semiconductor device in electricalcontact with the substrate through the eutectic bonding material.
 5. Thesemiconductor device of claim 1, wherein the first composition comprisessilicon and gold.
 6. The semiconductor device of claim 1, wherein thefirst composition comprises silicon and aluminum.
 7. A semiconductordevice comprising: a passivation layer over a substrate; a firsteutectic bonding material located over the passivation layer, the firsteutectic bonding material further having a first composition of eutecticmaterials and a second composition of eutectic materials different fromthe first composition; and a block located apart from the first eutecticbonding material, wherein the first eutectic bonding material comprisesa first material and the block comprises the first material.
 8. Thesemiconductor device of claim 7, further comprising a firstsemiconductor die electrically connected to the substrate through thefirst eutectic bonding material.
 9. The semiconductor device of claim 7,further comprising at least one trench located in the passivation layer.10. The semiconductor device of claim 9, wherein the first eutecticbonding material is at least partially located within the at least onetrench.
 11. The semiconductor device of claim 9, wherein the trench hasa depth of between about 0.5 μm and about 40 μm.
 12. The semiconductordevice of claim 7, wherein the first composition comprises aluminum andgermanium.
 13. A semiconductor device comprising: a first eutecticbonding material over a substrate, the first eutectic bonding materialhaving a first concentration of a first eutectic material; and a secondeutectic bonding material in physical connection with the first eutecticbonding material, the second eutectic bonding material having a secondconcentration of the first eutectic material different from the firstconcentration; further comprising a block of a second eutectic materialremoved from the first eutectic bonding material and the second eutecticbonding material, wherein the second eutectic bonding material comprisesa second eutectic material.
 14. The semiconductor device of claim 13,wherein the first concentration is higher than the second concentration.15. The semiconductor device of claim 13, wherein the first eutecticmaterial is aluminum.
 16. The semiconductor device of claim 15, whereinthe second eutectic bonding material comprises germanium.
 17. Thesemiconductor device of claim 15, wherein the second eutectic bondingmaterial comprises silicon.
 18. The semiconductor device of claim 1,wherein the block is a first block in a row of blocks.
 19. Thesemiconductor device of claim 7, wherein the block is a first block in aplurality of blocks located around the first eutectic bonding material,wherein the plurality of blocks comprises the first material.
 20. Thesemiconductor device of claim 13, further comprising a second block of asecond eutectic material removed from the first eutectic bondingmaterial and the second eutectic bonding material.